Watch the Gold Standard online guitar lesson by Brad Carlton from Chord Studies: Rock and Pop Progressions Vol. 1
A standard rock progression but with a twist at the end. Going from the familiar "A form" Bm chord to G is pretty straight forward. But, the twist comes in when you go from the "C form" of D, to the A chord and instead of barring all the way across with your first finger, you will just get the 3rd and 4th finger with the first and keep your second finger on the second string. Efficiency!